As shown in FIGS. 1 and 2, a gas turbine 200 generally includes a compressor 201 which produces compressed air, a plurality of combustors 1 of which each mixes a fuel with the compressed air produced by the compressor 201 and produces a combustion gas, and a turbine 202 which is driven by the combustion gas produced by the combustor 1. The combustor 1 includes a combustor inner cylinder 2 to which the compressed air and fuel are supplied to be burned, and a combustor transition piece 3 which introduces the combustion gas produced by the combustor inner cylinder 2 into a combustion gas passage 203 of the turbine 202. The combustors 1 are arranged in an annular shape so as to surround a turbine rotor, and each combustor 1 is connected to an inlet portion 203a of the combustion gas passage 203 within the turbine 202.
In each of the combustors 1, the combustor transition piece 3 is inserted into a casing 4 to be connected to the inlet portion 203a of the combustion gas passage 203, and the combustor inner cylinder 2 is connected to a base end of the combustor transition piece 3. As shown in FIGS. 2 and 3, an opening portion 4a of the casing 4 is blocked in such a manner that a cover body 7 is fixed to cover fixing bolt holes 4b which are cover fixing portions formed along an outer edge of the casing. As shown in FIG. 1, a plurality of pipes 8 is disposed around the plural combustors 1 arranged in an annular shape, wherein the pipes 8 include a fuel supply pipe to supply a fuel, a cooling air supply pipe to cool each combustor 1, etc.
The above-mentioned combustor 1 is assembled by the insertion of the combustor transition piece 3 and the combustor inner cylinder 2 into the casing 4 from the opening portion 4a in sequence after the compressor 201, the casing 4, and the turbine 202 are constructed. In addition, each member constituting the gas turbine 200 is worn out through the operation thereof, and is thus periodically inspected with an individual period of each member and replaced as necessary. In general, since the inspection period of the combustor 1 is short compared with the inspection periods of the turbine 202 and the compressor 201, there is an opportunity to detach and inspect the combustor 1. The combustor 1 itself has such a weight (for example, about 100 kg) that the combustor transition piece 3 or the combustor inner cylinder 2 cannot be independently lifted by a person, and it is difficult to gain a foothold because the combustor 1 is located above an installation surface 200a of the gas turbine 200 in the vicinity of the casing 4. For this reason, a variety of attaching and detaching jigs are proposed in order to inspect the combustor 1 (for example, see Patent Document 1).
Specifically, an attaching and detaching jig of a combustor transition piece is proposed in Patent Document 1. This attaching and detaching jig of the combustor transition piece includes a pair of guide portions which is provided within a casing and extends in the axial direction of a combustor, a pair of moving portions which is provided in the combustor transition piece and is movable along the guide portions, and an advancing and retracting mechanism which advances and retracts the combustor transition piece along the axial direction of the combustor by moving each moving portion along the guide portions.
The advancing and retracting mechanism includes a ball screw which is disposed along the guide portions and rotatably supported, and a nut member which is threaded onto the ball screw and fixed to the combustor transition piece. In such a configuration, the nut member moves along the ball screw as the ball screw rotates, such that the combustor transition piece advances and retracts along the axial direction of the combustor.